The countries in the Central and Eastern European region and in the former Soviet Union republics have the most energy-poor people in Europe. This is mainly due to high energy prices and poor energy efficiency of the buildings, heating systems and household appliances. In this region, the housing stock is predominantly privately-owned and characterised by a large percentage of multi-family apartment blocks. Undertaking renovation works in multi-family buildings requires coordinated action among the apartment owners. To address the complex roots of energy poverty, there is a need to develop a new approach to make interventions affordable, substantially influence energy costs and consequently reduce the high energy poverty level in the CEE and CIS region. ComAct aims to make impactful energy-efficient improvements in multi-family apartment buildings in the Central and Eastern European (CEE) region and in the former Soviet Union republics (CIS region) affordable and manageable for energy-poor communities as well as to create the necessary assistance conditions for lifting them out of energy poverty.